Signal input of existing Universal Serial Bus (USB) modems are implemented by adopting a Flexible Printed Circuit (FPC). The signal input apparatuses of a push-pull USB stick include the FPC connected to a Printed Circuit Board (PCB) and a support fixed together with the FPC. A USB plug and the support are an integrated structure. A horizontal return spring and a push button are disposed on the support, and the support serves as a movable mechanism. The support loaded with the USB plug can retract or project out after the push button is pushed so that the USB modem can be in non-working or working state. The USB modem transmits data through the FPC and the PCB. During the implementation of the embodiments of the present utility model, the inventors find that as such existing signal input apparatus implements signal input by adopting an FPC, the FPC may easily wear out, thereby reducing the service life of the USB modem and increasing the implementation cost of the USB modem.